I 90 over Jefferson River Overflow
FairGallatin County, Montana · Three Forks · Structure no. I00090277+08261
- Built
- 1969
- 56 years old
- Condition
- Fair
- inspected July 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 255 ft
- 4 main spans
- Daily traffic
- 8,575
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I 90 over Jefferson River Overflow is a prestressed concrete stringer/multi-beam or girder carrying I 90 over Jefferson River Overflow in Gallatin County, Montana. It was built in 1969, so it is 56 years old, older than the Montana average of 47 years.
The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
It carries about 8,575 vehicles a day, roughly 14% of them trucks, projected to reach 9,689 by 2043. The structure is 255 ft (77.7 m) long and 41 ft wide.
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was I 90 over Jefferson River Overflow built?
It was built in 1969, making it 56 years old in 2025.
What condition is I 90 over Jefferson River Overflow in?
The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in July 2024.
How much traffic does I 90 over Jefferson River Overflow carry?
About 8,575 vehicles per day (2023 count), of which roughly 14% are trucks.
How long is I 90 over Jefferson River Overflow?
The structure is 255 ft (77.7 m) long with a longest span of 70 ft (21.3 m) and a deck 41 ft wide.
Who owns I 90 over Jefferson River Overflow?
It is owned by the State Highway Agency.